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2. Impact of preS1 Evaluation in the Management of Chronic Hepatitis B Virus Infection.

Author

Hayashi, Yuka, Tajiri, Kazuto, Ozawa, Tatsuhiko, Angata, Kiyohiko, Sato, Takashi, Togayachi, Akira, Nagashima, Izuru, Shimizu, Hiroki, Murayama, Aiko, Muraishi, Nozomu, Narimatsu, Hisashi, and Yasuda, Ichiro

Subjects
HEPATITIS B, HEPATITIS associated antigen, CHRONIC hepatitis B, MONOCLONAL antibodies, EPITOPES
Abstract

Background and Objectives: The measurement of hepatitis B surface antigen (HBsAg) is essential for managing chronic hepatitis B virus infection (CHB). HBsAg consists of three different surface envelope proteins: large, middle, and small HB surface proteins. However, in clinical practice, it is not common to evaluate each of these HB surface proteins separately. Materials and Methods: In this study, we investigated preS1 expression using seven monoclonal antibodies (mAbs) in 68 CHB patients, as well as examining their antigenicity. Results: Although the seven mAbs had been derived from genotype (Gt) C, they could recognize preS1 with Gts A to D. The epitopes were concentrated within the aa33-47 region of preS1, and their antigenicity was significantly reduced by an aa45F substitution. We found that preS1 expression remained consistent regardless of HBsAg levels and different Gts in CHB patients, in contrast to what was observed in SHBs. Conclusions: These results suggest that the antigenic epitope is preserved among different Gts and that the expression pattern of preS1 is altered during CHB, highlighting its vital role in the HBV infection cycle. Our present results suggest preS1 is a promising therapeutic target in CHB. [ABSTRACT FROM AUTHOR]

Published
2024
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5. Core fucose‐specific Pholiota squarrosa lectin (PhoSL) as a potent broad‐spectrum inhibitor of SARS‐CoV‐2 infection

Author

Yamasaki, Kazuhiko, primary, Adachi, Naruhiko, additional, Ngwe Tun, Mya Myat, additional, Ikeda, Akihito, additional, Moriya, Toshio, additional, Kawasaki, Masato, additional, Yamasaki, Tomoko, additional, Kubota, Tomomi, additional, Nagashima, Izuru, additional, Shimizu, Hiroki, additional, Tateno, Hiroaki, additional, and Morita, Kouichi, additional

Published
2022
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8. O-glycosylated HBsAg peptide can induce specific antibody neutralizing HBV infection

Author

Angata, Kiyohiko, primary, Wagatsuma, Takanori, additional, Togayachi, Akira, additional, Sato, Takashi, additional, Sogabe, Maki, additional, Tajiri, Kazuto, additional, Ozawa, Tatsuhiko, additional, Nagashima, Izuru, additional, Shimizu, Hiroki, additional, Iijima, Sayuki, additional, Korenaga, Masaaki, additional, Kuno, Atsushi, additional, Kaji, Hiroyuki, additional, Mizokami, Masashi, additional, and Narimatsu, Hisashi, additional

Published
2022
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9. Core fucose‐specific Pholiota squarrosa lectin (PhoSL) as a potent broad‐spectrum inhibitor of SARS‐CoV‐2 infection.

Author

Yamasaki, Kazuhiko, Adachi, Naruhiko, Ngwe Tun, Mya Myat, Ikeda, Akihito, Moriya, Toshio, Kawasaki, Masato, Yamasaki, Tomoko, Kubota, Tomomi, Nagashima, Izuru, Shimizu, Hiroki, Tateno, Hiroaki, and Morita, Kouichi

Subjects
SARS-CoV-2, GLYCANS, PEPTIDES
Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) spike protein (S protein) is highly N‐glycosylated, and a "glycan shield" is formed to limit the access of other molecules; however, a small open area coincides with the interface to the host's receptor and also neutralising antibodies. Most of the variants of concern have mutations in this area, which could reduce the efficacy of existing antibodies. In contrast, N‐glycosylation sites are relatively invariant, and some are essential for infection. Here, we observed that the S proteins of the ancestral (Wuhan) and Omicron strains bind with Pholiota squarrosa lectin (PhoSL), a 40‐amino‐acid chemically synthesised peptide specific to core‐fucosylated N‐glycans. The affinities were at a low nanomolar level, which were ~ 1000‐fold stronger than those between PhoSL and the core‐fucosylated N‐glycans at the micromolar level. We demonstrated that PhoSL inhibited infection by both strains at similar submicromolar levels, suggesting its broad‐spectrum effect on SARS‐CoV‐2 variants. Cryogenic electron microscopy revealed that PhoSL caused an aggregation of the S protein, which was likely due to the multivalence of both the trimeric PhoSL and S protein. This characteristic is likely relevant to the inhibitory mechanism. Structural modelling of the PhoSL–S protein complex indicated that PhoSL was in contact with the amino acids of the S protein, which explains the enhanced affinity with S protein and also indicates the significant potential for developing specific binders by the engineering of PhoSL. [ABSTRACT FROM AUTHOR]

Published
2023
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11. Study of 400 MHz microwave conduction loss effect for a hydrolysis reaction by thermostable β-Glucosidase HT1

Author

Nagashima, Izuru, Sugiyama, Jun-ichi, and Shimizu, Hiroki

Abstract

Microwave irradiation at different frequencies gave molecular selective effects, namely higher frequency microwave effects for waters while lower frequency effects for ions. We already reported that 2.45 GHz and 5.80 GHz microwave irradiation gave different results for a hydrolysis reaction by thermostable β-Glucosidase HT1. Here, we designed and made a reactor, employed 400 MHz microwave irradiation, and studied the effectiveness of 400 MHz microwave for HT1 reaction, then 400 MHz and 2.45 GHz had the ability to accelerate HT1 reaction. In consideration of the general mechanism of enzymatic glycoside hydrolysis, our results would be reasonable if ions are key reaction species because 400 MHz microwave activated ions selectively. In addition, the phenomenon that 400 MHz microwave would not affect water molecules by dielectric heating might contribute the enzyme stability. This report should support that microwave is not only a tool to heat reactions efficiently but also can bring unique effects for reactions.Graphical Abstract400 MHz microwave works ions selectively and accelerated HT1 enzymatic reaction.

Published
2023
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16. Artificial golgi apparatus: globular protein-like dendrimer-facilitates fully automated enzymatic glycan synthesis

Author

Matsushita, Takahiko, Nagashima, Izuru, Fumoto, Masataka, Ohta, Takashi, Yamada, Kuriko, Shimizu, Hiroki, Hinou, Hiroshi, Naruchi, Kentaro, Ito, Takaomi, Kondo, Hirosato, and Nishimura, Shin-Ichiro

Subjects
Dendrimers -- Structure, Dendrimers -- Chemical properties, Globular proteins -- Structure, Globular proteins -- Chemical properties, Glucosamine -- Chemical properties, Glucosamine -- Structure, Golgi apparatus -- Research, Polysaccharides -- Chemical properties, Polysaccharides -- Structure, Chemistry
Abstract

A new method is developed for automated glycan synthesis that has used the enzymatic approach and a dendrimer as an ideal support within the chemical process. The protocol has allowed for the fully automated enzymatic synthesis of silyl Lewis X tetrasaccharide derivatives from a simple N-acetyl-D-glucosamine linked to an aminooxy-functionalized G7 dendrimer.

Published
2010

19. p62/SQSTM1 Plays a Protective Role in Oxidative Injury of Steatotic Liver in a Mouse Hepatectomy Model

Author

1000060706505, Haga, Sanae, Ozawa, Takeaki, 1000060451431, Yamada, Yuma, Morita, Naoki, Nagashima, Izuru, Inoue, Hiroshi, Inaba, Yuka, Noda, Natsumi, 1000060344511, Abe, Riichiro, 1000070114402, Umezawa, Kazuo, 1000080256510, Ozaki, Michitaka, 1000060706505, Haga, Sanae, Ozawa, Takeaki, 1000060451431, Yamada, Yuma, Morita, Naoki, Nagashima, Izuru, Inoue, Hiroshi, Inaba, Yuka, Noda, Natsumi, 1000060344511, Abe, Riichiro, 1000070114402, Umezawa, Kazuo, 1000080256510, and Ozaki, Michitaka

Abstract

Aims: Liver injury and regeneration involve complicated processes and are affected by various physio-pathological factors. We investigated the mechanisms of steatosis-associated liver injury and delayed regeneration in a mouse model of partial hepatectomy. Results: Initial regeneration of the steatotic liver was significantly delayed after hepatectomy. Although hepatocyte proliferation was not significantly suppressed, severe liver injury with oxidative stress (OS) occurred immediately after hepatectomy in the steatotic liver. Fas-ligand (FasL)/Fas expression was upregulated in the steatotic liver, whereas the expression of antioxidant and anti-apoptotic molecules (catalase/MnSOD/Ref-1 and Bcl-2/Bcl-xL/FLIP, respectively) and p62/SQSTM1, a steatosis-associated protein, was downregulated. Interestingly, pro-survival Akt was not activated in response to hepatectomy, although it was sufficiently expressed even before hepatectomy. Suppression of p62/SQSTM1 increased FasL/Fas expression and reduced nuclear factor erythroid 2-related factor-2 (Nrf-2)-dependent antioxidant response elements activity and antioxidant responses in steatotic and nonsteatotic hepatocytes. Exogenously added FasL induced severe cellular OS and necrosis/apoptosis in steatotic hepatocytes, with only the necrosis being inhibited by pretreatment with antioxidants, suggesting that FasL/Fas-induced OS mainly leads to necrosis. Furthermore, p62/SQSTM1 re-expression in the steatotic liver markedly reduced liver injury and improved liver regeneration. Innovation: This study is the first which demonstrates that reduced expression of p62/SQSTM1 plays a crucial role in posthepatectomy acute injury and delayed regeneration of steatotic liver, mainly via redox-dependent mechanisms. Conclusion: In the steatotic liver, reduced expression of p62/SQSTM1 induced FasL/Fas overexpression and suppressed antioxidant genes, mainly through Nrf-2 inactivation, which, along with the hypo-responsiveness of Akt, caused posth

Published
2014

20. p62/SQSTM1 Plays a Protective Role in Oxidative Injury of Steatotic Liver in a Mouse Hepatectomy Model

Author

Haga, Sanae, Ozawa, Takeaki, Yamada, Yuma, Morita, Naoki, Nagashima, Izuru, Inoue, Hiroshi, Inaba, Yuka, Noda, Natsumi, Abe, Riichiro, Umezawa, Kazuo, Ozaki, Michitaka, Haga, Sanae, Ozawa, Takeaki, Yamada, Yuma, Morita, Naoki, Nagashima, Izuru, Inoue, Hiroshi, Inaba, Yuka, Noda, Natsumi, Abe, Riichiro, Umezawa, Kazuo, and Ozaki, Michitaka

Abstract

Aims: Liver injury and regeneration involve complicated processes and are affected by various physio-pathological factors. We investigated the mechanisms of steatosis-associated liver injury and delayed regeneration in a mouse model of partial hepatectomy. Results: Initial regeneration of the steatotic liver was significantly delayed after hepatectomy. Although hepatocyte proliferation was not significantly suppressed, severe liver injury with oxidative stress (OS) occurred immediately after hepatectomy in the steatotic liver. Fas-ligand (FasL)/Fas expression was upregulated in the steatotic liver, whereas the expression of antioxidant and anti-apoptotic molecules (catalase/MnSOD/Ref-1 and Bcl-2/Bcl-xL/FLIP, respectively) and p62/SQSTM1, a steatosis-associated protein, was downregulated. Interestingly, pro-survival Akt was not activated in response to hepatectomy, although it was sufficiently expressed even before hepatectomy. Suppression of p62/SQSTM1 increased FasL/Fas expression and reduced nuclear factor erythroid 2-related factor-2 (Nrf-2)-dependent antioxidant response elements activity and antioxidant responses in steatotic and nonsteatotic hepatocytes. Exogenously added FasL induced severe cellular OS and necrosis/apoptosis in steatotic hepatocytes, with only the necrosis being inhibited by pretreatment with antioxidants, suggesting that FasL/Fas-induced OS mainly leads to necrosis. Furthermore, p62/SQSTM1 re-expression in the steatotic liver markedly reduced liver injury and improved liver regeneration. Innovation: This study is the first which demonstrates that reduced expression of p62/SQSTM1 plays a crucial role in posthepatectomy acute injury and delayed regeneration of steatotic liver, mainly via redox-dependent mechanisms. Conclusion: In the steatotic liver, reduced expression of p62/SQSTM1 induced FasL/Fas overexpression and suppressed antioxidant genes, mainly through Nrf-2 inactivation, which, along with the hypo-responsiveness of Akt, caused posth

Published
2014

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